Objective To observe whether the ¹⁸F-FDG uptake in pulmonary benign nodular lesions is uniform, and to analyze the nonuniform characteristics, and then to investigate whether it is helpful for differential diagnosis.

Methods Sixty cases of pulmonary benign nodular lesions were collected with examination of ¹⁸F-FDG PET/CT. After measuring the maximum standardized uptake value (SUV_max), 2 senior radiologists visually analyzed the uniformity of ¹⁸F-FDG uptake, and the uneven shape was divided into irregular uptake, no uptake in part of nodule, center nodular uptake and edge ring uptake respectively. The location and wide basal adhesion to adjacent pleural were also recorded.

Results With SUV_max≥2.5 as criteria for differential diagnosis the misdiagnostic rate was 56.7% and 38.3% with both SUV_max and CT signs in 60 cases of benign nodular lesions. Among 40 cases the ¹⁸F-FDG uptake was not uniform with the irregular uptake in 15 cases, no uptake partially in 17 cases, center intake in 5 cases and edge ring uptake in 3 cases. There were 10 cases with lesions located in the apicoposterior segment of both upper lobes of the 14 tuberculosis cases. In 24 cases the lesions adhered the adjacent pleural in broad base and infectious lesions had the higher proportion(14/21).

Conclusions Ununiformity of ¹⁸F-FDG uptake often appears in pulmory benign nodular lesions, and may be a valuable sign in the differential diagnosis. Infectious lesions should be considered if nodular lesions presented with broad pleural adhesions.